Methods and devices for urethral treatment

ABSTRACT

Apparatus and methods are described for dilating a portion of a urethra surrounded by an enlarged prostate. The apparatus includes dilation device, and a delivery device including a balloon. The delivery device is configured to deliver the dilation device and the balloon to the portion of the urethra, while the dilation device is disposed in a helical configuration on the delivery device. Upon the balloon and the dilation device being disposed at the portion of the urethra, the delivery device is configured to expand the balloon, thereby expanding the portion of the urethra, and to cause the dilation device to radially expand from the helical configuration to an arc configuration. Subsequently, the delivery device is configured to implant the dilation device, from outside the balloon, into tissue of the prostate surrounding the portion of the urethra, while the portion of the urethra is expanded by the balloon.

RELATED APPLICATIONS

The present application is a continuation of U.S. Pat. Application No.16/554,774, filed on Aug. 29, 2019 (published as US 2019/0381291), whichis a continuation of U.S. Pat. Application No. 14/967,308 filed on Dec.13, 2015 (issued as US 10,406,333), which is a division of U.S. Pat.Application No. 13/257,651 filed on Sep. 20, 2011 (now abandoned), whichis a National Phase of PCT Patent Application No. PCT/IL2010/000229having International Filing Date of Mar. 21, 2010 (published as WO10/106543), which claims the benefit of priority of U.S. ProvisionalPat. Application No. 61/202,634 filed Mar. 20, 2009. The contents of theabove applications are all incorporated by reference as if fully setforth herein in their entirety.

FIELD OF THE INVENTION

The present invention, in some embodiments thereof, relates to methodsand devices for treatment of intrabody lumens, and, more particularly,but not exclusively, to methods and devices for dilating and/orassisting in dilation and/or maintaining dilation of the urethra torelieve obstruction resulting, for example from benign prostatichyperplasia (BPH).

BACKGROUND OF THE INVENTION

It is common for the prostate gland to become enlarged as a man ages. Asa male matures, the prostate goes through two main periods of growth,first early in puberty, and then again at around age 25, when the growthbegins, and continues on through life. One of the effects of thiscontinued growth can be pressure on the urethra, the passage throughwhich urine passes from the bladder and the penis.

The urethra is surrounded by the prostate for part of its length. Withinthe confines of the prostate, the urine flows through a passage having agenerally triangular cross-section. As the prostate enlarges, the layerof tissue surrounding the prostate restricts the prostate from expandingoutward, causing the prostate to constrict the urethral passage. Thecondition of an enlarged, non-cancerous prostate is called benignprostatic hyperplasia (BPH), or benign prostatic hypertrophy.

Though the prostate continues to grow during most of a man’s life, BPHrarely causes symptoms before age 40, but more than half of men in theirsixties and as many as 90 percent in their seventies and eighties havesome symptoms of BPH. BPH can make it difficult to the bladder tocompletely empty, and is associated with other urinary system problemswell known in the medical field.

Current Treatment

Men who have BPH with symptoms usually need some kind of treatment atsome time. Although the need for treatment is not usually urgent,doctors generally advise treatment once the problems become bothersomeor present a health risk.

The most commonly used treatments for BPH include drug therapy,minimally invasive mechanical treatment, and surgery.

Among the drugs approved for example, by the U.S. FDA, are Finasteride(Proscar), dutasteride (Avodart), terazosin (Hytrin), doxazosin(Cardura), tamsulosin (Flomax), and alfuzosin (Uroxatral). These drugsact by relaxing the smooth muscle of the prostate and bladder neck toimprove urine flow and to reduce bladder outlet obstruction. Use offinasteride and doxazosin together has also been found to be moreeffective than using either drug.

Drug treatment may only be partially effective in some cases.Researchers have therefore developed a number of mechanical proceduresthat relieve BPH symptoms but are less invasive than conventionalsurgery. These include transurethral microwave thermotherapy (TUMT),which uses microwaves to heat and destroy portions of prostate tissue,transurethral needle ablation (TUNA), which employs low-levelradio-frequency energy delivered through twin needles to burn awayselected regions of the enlarged prostate, and water-inducedthermotherapy, which uses heated water to destroy portions of prostatetissue. The use of ultrasound waves to destroy prostate tissue is alsoundergoing clinical trials in the United States.

Urethral stents have also been employed in some instances, with varyingdegrees of effectiveness.

Surgical removal of part of the prostate, thereby reducing pressureagainst the urethra is often regarded as the best long-term solution forpatients with BPH. Among the types of surgery commonly employed istransurethral surgery which requires no external incision. Suchprocedures include transurethral resection of the prostate (TURP), bywhich prostate tissue is removed, transurethral incision of the prostate(TUIP), by which the urethra is widened by making a few small cuts inthe bladder neck where the urethra joins the bladder, and in theprostate gland itself, and laser induced prostate tissue removal.

In the few cases where transurethral surgical procedures are notindicated, open surgery, which requires an external incision, may beused.

SUMMARY OF THE INVENTION

According to an aspect of some embodiments of the invention, a methodfor dilating a urethra is provided according to which a dilation deviceis implanted around the outside of a urethra in an area affected by anenlarged prostate with at least part of the dilation device embedded ina surrounding enlarged prostate, thereby preventing clinicallysignificant compression of the urethra.

According to some embodiments, the dilation device is installedtransurethrally.

According to some embodiments, the dilation device is implanted by beingscrewed into the tissue of the prostate.

According to some embodiments, the dilation device is implanted by beingpushed into the tissue of the prostate.

According to some embodiments, the dilation device is implanted by beingadvanced into the tissue of the prostate using an overtube.

According to some embodiments, the dilation device is implanted, andexpanded or allowing to expand post-implantation.

According to some embodiments, the dilation device is in the form of aspiral wire.

According to some embodiments, the dilation device is in the form of oneor more separate curved sections.

According to some embodiments, the dilation device is formed of amaterial which expands outwardly around the urethra during and/or afterimplantation.

According to some embodiments, prior to or during before implantation,the urethra is shaped using an expandable element.

According to some embodiments, the expandable element is not rotatedduring implantation.

According to some embodiments, the expandable element is a balloon.

According to some embodiments, the length and position of the dilationdevice is selected not to interfere with an inner bladder valve.

According to some embodiments, the dilation device provides clearancebetween the enlarged prostate and a lumen of the urethra, and preventsrecompression of the urethra due to further enlargement of the prostate.

According to an aspect of some embodiments of the invention, apparatusfor implanting a urethral dilation device is provided having a mountingdevice configured to carry the dilation device, and a releasablyattached movable holder, the mounting device and holder being configuredto deliver the dilation device though a working channel to a desiredposition in a urethra, and to implant the dilation device through a wallof the urethra to a position surrounding the urethra.

According to some embodiments, a delivery sheath is provided to receivethe dilation device before placement thereof on the mounting device.

According to some embodiments, the delivery sheath is of a shapegenerally conforming to that of the dilation device.

According to some embodiments, the dilation device is formed of aresilient material, and the mounting device is configured to permit areduction of a transverse dimension of the dilation device as it passesthough the working channel.

According to some embodiments, the implantation apparatus includes aurethral expander.

According to some embodiments, the urethral expander is configured to berotatably coupled to the holder.

According to some embodiments, the urethral expander is configured tohave a known position relative to the holder.

According to some embodiments, the urethral expander is configured tolie to a side of the holder.

According to some embodiments, the urethral expander includes at leastone guide channel for the dilation device.

According to some embodiments, the urethral expander is a balloon.

According to an aspect of some embodiments of the invention, a dilationdevice is provided for a urethra partially occluded by an enlargedprostate having a curved element configured to be implanted around aurethra and add resilience to a urethral lumen.

According to some embodiments, the has a spiral shape.

According to some embodiments, the dilation device is a plurality ofcurved segments.

According to some embodiments, the dilation device is formed of aresilient material.

According to some embodiments, the dilation device is configured fortransurethral implantation.

According to some embodiments, the mounting device and the holder areattached together.

According to some embodiments, the delivery device includes a cageconfigured to surround the dilation device during implantation.

According to some embodiments, the cage includes an opening allowing thedilation device to exit for implantation.

According to some embodiments, the cage is configured to compress thedilation device and prevent it from expanding while being delivered forimplantation.

According to an aspect of some embodiments of the invention, a method isprovided for supporting a body lumen, in which a dilation device isimplanted around the outside of the lumen in an area affected by acompression tissue with at least part of the dilation device embedded ina surrounding tissue, thereby preventing clinically significantcompression of the lumen.

Unless otherwise defined, all technical and/or scientific terms usedherein have the same meaning as commonly understood by one of ordinaryskill in the art to which the invention pertains. Although methods andmaterials similar or equivalent to those described herein can be used inthe practice or testing of embodiments of the invention, exemplarymethods and/or materials are described below. In case of conflict, thepatent specification, including definitions, will control. In addition,the materials, methods, and examples are illustrative only and are notintended to be necessarily limiting.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Some embodiments of the invention are herein described, by way ofexample only, with reference to the accompanying drawings. With specificreference now to the drawings in detail, it is stressed that theparticulars shown are by way of example and for purposes of illustrativediscussion of embodiments of the invention. In this regard, thedescription taken with the drawings makes apparent to those skilled inthe art how embodiments of the invention may be practiced.

In the drawings:

FIG. 1 is a flow diagram illustrating a method of supporting andoptionally dilating a generally cylindrical organ, for example, aurethra, to alleviate symptoms of an enlarged prostate relating tourinary flow blockage according to some embodiments of the invention;

FIG. 2 is a fragmentary schematic illustration of an enlarged prostateand urethra, helpful in understanding the method of FIG. 1 ;

FIG. 3A shows a dilation device in the form of a spiral wire accordingto some embodiments of the invention, which can be implanted, forexample, by the method of FIG. 1 ;

FIGS. 3B and 3C show exemplary alternative enlarged cross-sections forthe wire of FIG. 3A;

FIGS. 3D-3F illustrate an implantation device suitable for use with thedevice of FIGS. 3A-3C and progression of a method of implantationaccording to some embodiments of the invention, based, for example, onthe method of FIG. 1 ;

FIG. 4 is a flow diagram illustrating a urethral treatment methodaccording to some other embodiments of the invention, as for example,the device of FIG. 3A;

FIGS. 5A-5E are a schematic illustration of a variation of theimplantation device of FIGS. 3D-3F and progression of a method ofimplantation according to some embodiments of the invention, as forexample, the method of FIG. 4 ;

FIG. 6 is a flow diagram illustrating a urethral treatment methodaccording to some embodiments of the invention;

FIG. 7A is a fragmentary schematic illustration of an enlarged prostateand a urethra in cross-section helpful in understanding the method ofFIG. 6 ;

FIGS. 7B-7E shows a dilation device in the form of separate curvedsections according to some embodiments of the invention, which can beimplanted, for example, by the method of FIG. 6 , and progression of amethod of implantation, for example, the method of FIG. 6 ;

FIG. 8A shows, in schematic form, an implantation apparatus according tosome embodiments of the invention by which separate curved wires can beimplanted, for example, by the method of FIG. 6

FIG. 8B shows a variation of the implantation apparatus of FIG. 8A,according to some embodiments of the invention;

FIG. 9 illustrates in schematic form an implantation apparatus accordingto some embodiments of the invention which may be used to practice themethod, for example, of FIG. 10 , for implanting spiral wires orseparate curved sections; and

FIG. 10 is a flow diagram illustrating a urethral treatment methodutilizing the apparatus of FIG. 9 , according to some embodiments of theinvention.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

The present invention, in some embodiments thereof, relates to methodsand/or devices for treatment of intrabody lumens, and, moreparticularly, but not exclusively, to methods and devices for dilatingand/or assisting in dilation and/or maintaining dilation of the urethrato relieve obstruction resulting, for example, from benign prostatichyperplasia (BPH).

An aspect of some embodiments of the invention relates to treatment ofan obstructed urethra, by implanting one or more structural elements ina prostate gland, optionally near a wall of the urethra. Optionally,such structural elements prevent collapsing of the urethra by thepressure of the prostate. A potential benefit of such positioning ofstructural elements is that urine flow contacts only natural endothelialtissue, onto which it does not aggregate. A potential benefit of suchpositioning is that endothelial tissue damage is reduced (e.g., to asmall number of puncture points), potentially reducing complicationsand/or restenosis. A potential benefit of such positioning is thatpressure damage to the urethral tissue may be reduced. A potentialbenefit of such positioning is that migration of the structural elementmay be reduced compared to that of a stent and/or use less invasiveanchoring, optionally preventing damage to bladder valves and/orpreventing of urine leakage.

According to an aspect of some embodiments of the invention, a dilationdevice, for example, a curved wire, optionally, an elongated spiral orone or more curved (for example, generally C-shaped arcs), is implantedaround the urethra within the confines of the prostate to help treatsymptoms of an enlarged prostate, for example, compression of theurethral passage, and to prevent further compression of the urethralpassage due to continued enlargement of the prostate. For convenience,the various possible shapes of the dilation device or parts thereof willsometimes be collectively referred to as a “wire”.

The wire is optionally made of a biocompatible, for example, metallicmaterial, or of a biodegradable material. Optionally, the wire has agenerally rounded or a generally flat cross-section. Optionally, thewire has a widened tip (or tips) and/or edges to prevent piercing damageto the urethra and/or prostate during and after implantation.

Optionally, according to an aspect of some embodiments of the invention,the wire is formed of a resilient or elastic material and/or isconfigured so that it is able to expand during and/or afterimplantation, e.g., being formed of a super-elastic or shape-memorymaterial configured to have a desired final shape in the body.

Optionally, in the case of a spiral wire, the length along the urethrais short, for example, 1 cm or less in length, to provide a localdilation, or longer than 1 cm to open longer areas in the urethra.Optionally, several spirals may be implanted along a length of theurethra, e.g., at axially different locations, optionally with someoverlap therebetween or with spacing therebetween.

Optionally, one or more separate curved sections may be spaced along theurethra, and/or extend circumferentially around the urethra. Optionally,spirals and separate curved sections may be used together. Optionally,multiple separate curved sections may be installed sequentially orsimultaneously, for example, with multiple such sections encircling theurethra. In some embodiments, the urethra is not completely encircled bysuch implantations.

According to an aspect of some embodiments of the invention, the wire isprovided with a drug coating, for example, sirolimus or paclitaxel,etc., which is eluted over time, for example, to treat the prostate(e.g., cause shrinkage or reduce growth) and/or to prevent restenosis.Optionally, the wire may be made of or coated with a radioactivematerial, or formed of a material capable of being heated by RF energy,for example, by microwaves.

According to an aspect of some embodiments of the invention, the wire isimplanted using a delivery device inserted into a urethra through aworking channel provided, for example, by a cystoscope, or a catheter,also inserted in the urethra. Optionally, the implantation process isguided visually through the working channel, or in other ways, forexample, by ultrasound.

According to an aspect of some embodiments of the invention, the urethrais shaped before implantation, for example using an expanding balloon.Optionally or alternatively, the balloon is used to guide insertion ofthe device. Optionally, the balloon is maintained in place and includesa guide to guide insertion of the device. In an alternative embodiment,the balloon is maintained in place while a device delivery system isrotated.

In an exemplary embodiment of the invention, one of three insertionmethods are used: pushing the wire through the urethral wall into theprostate, screwing the wire around the urethra after a first insertioninto the prostate, and inserting the wire covered with an overtube orother delivery system and/or stiffener into the prostate and thenretracting the over tube. Other implantation methods may be used aswell. In some embodiments, a plurality of wires is insertedsimultaneously, for example, at same or different axial locations alongthe urethra.

In an exemplary embodiment of the invention, the wire is loaded in adelivery system in a linear configuration. A plurality of wires may beloaded simultaneously, for example, for sequential and/or parallelimplantation. In other embodiments, the wire is loaded in a nonlinearconfiguration, for example, as a helix or folded. Such a helixconfiguration may also be used for arc-section devices.

Optionally, the delivery device includes a first part on which the wireis mounted and a second part which is coupled with the first part whichis used to move the wire to a desired location for implantation.

Optionally, according to an aspect of some embodiments of the invention,a wire in the form of a spiral is inside a part of the delivery devicewhich surrounds the wire. Optionally, the surrounding part is a sheaththat fits closely around the wire, or is in the form of a cagesurrounding the outside of the wire in its entirely for delivery to adesired implantation site. The cage optionally prevents expansion of awire which has been compressed during delivery.

According to an aspect of some embodiments of the invention, the wire isimplanted outside the urethra by screwing it to the tissue of theprostate surrounding the urethra. Optionally, for a wire deliveredinside a sheath, the wire is implanted by screwing the sheath itselfinto the tissue of the prostate, and a pusher device is provided toexpel the wire from the sheath, and hold the wire in place while thesheath is unscrewed and withdrawn through the working channel.

In some cases, the sheath can be removed by pulling back. For example,where the sheath is soft and serves to reduce friction between the wireand prostate tissue, the sheath may be pulled back.

According to an aspect of some embodiments of the invention, when thedelivery device includes an inflatable balloon for expanding the urethrabefore implantation as mentioned above, the balloon is positionedaxially before inflation, or at the circumference of the urethra.Optionally, the balloon includes one or more guide pockets or channels(e.g., on its surface or in its body) through which the wire is passedduring implantation. Optionally, the wire is guided during delivery andimplantation by a holder separate from the balloon.

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not necessarily limited in itsapplication to the details of construction and the arrangement of thecomponents and/or methods set forth in the following description and/orillustrated in the drawings and/or the Examples. The invention iscapable of other embodiments or of being practiced or carried out invarious ways. For example, some embodiments are intended for dilation ofother generally cylindrical body cavities such as a bile duct in case ofpancreatic or other carcinomas, intestine, e.g. colon carcinoma, bloodvessels, or esophagus. In an exemplary embodiment of the invention, insuch applications, the length, diameter of coil (e.g., to match tissuelumen) and/or mechanical properties of the wire are adjusted accordingto the application. Optionally, in some body lumens, implantation iswithin a wall of the lumen. In other embodiments, implantation isoutside the wall of the lumen, for example, in surrounding tissue.

Turning first to FIG. 1 , there is shown a flow chart for practice of amethod for dilating a urethra according to some embodiments of theinvention. This will be discussed in the context of the schematicillustration of a urethra and a surrounding prostate in FIG. 2 , aurethra dilation device in the form of a spiral wire illustrated inFIGS. 3A-3C, and an exemplary delivery device illustrated in FIGS.3D-3F. These will be discussed in detail below.

For reference purposes, in FIG. 2 , a urethra 10 is shown compressed byan enlarged prostate 12. Also shown is a working channel 14, forexample, of a cystoscope or a catheter, which enlarges the urethra at 15and provides a pathway for insertion of a delivery device or wire.

With specific reference to FIG. 1 , at 16, a dilation device in the formof a spiral wire is placed on a mounting tube. As noted above, such adevice may have other functions in addition to or instead of dilation.Optionally, it is placed at the proximal end of the mounting tube, i.e.,toward the physician. At 18, the proximal end of the spiral wire isattached to a holder which, in turn, is connected to the mounting tube.At 20, a working channel is inserted into the urethra. Alternatively,the working channel may be inserted in the urethra initially and thewire loaded thereafter. In some embodiments, a very long wire is used,which is snipped after a desired length is inserted. A snipping tool(not shown) may be provided at the distal end of the working channel,optionally as a closable sharp annulus, or as a separate inserted tool.

At 22 and 24, the wire, the holder and the mounting tube are passedthrough the working channel to a desired location for implantation. Inan exemplary embodiment of the invention, the location is selected sothat the wire will support the urethra along the entre length of theprostate, possibly with some proximal extension. Optionally oralternatively, the location (and/or length of wire) is selected so thatthe bladder neck will not be damaged. Optionally or alternatively, thelocation is selected so that operation on the inner bladder valve is notinterfered with. Optionally or alternatively, at least some wire isinserted near the inner valve, possibly resisting over-compressionthereof by an enlarged prostate.

At 26 and 28, when the distal end of the wire is out of the workingchannel, the mounting tube is rotated and advanced to screw the spiralwire through the tissue surrounding the urethra where it is releasedfrom the holder and lodged in the prostate around the urethra.Optionally, a stylet (e.g., part of the delivery system or a separaterod, and in some embodiments, a balloon) is present in the urethra, tocontrol the positioning of the wire relative to the urethral wall.Optionally or alternatively, the wire is inserted backwards, with theexposed tip of the wire being proximal to the far end of the deliverysystem which system may be inserted deeper into the body than theprostate. In an alternative embodiment, the wire is bent in an oppositehelix to its natural shape, so that while it is fed forward, once thewire exits the delivery tube it screws proximally, rather than distally

At 30, the mounting tube is screwed back (or pulled back) into theworking channel, and then removed. Then, at 32, the working channel isremoved from the urethra.

Optionally, a stent, for example, a temporary stent, is implanted in theurethra, for example, until it heals and/or the wire sets in place.Optionally or alternatively, a catheter for urinary drainage isimplanted.

With reference now to FIGS. 3A-3C, a dilation wire 60 shown in the formof an elongated spiral, with two alternative exemplary cross-sectionsshown at FIG. 3B and FIG. 3C. Optionally, wire 60 has a circularcross-section, as indicated at 61 a in FIG. 3B, or has a flattenedcross-section as indicated at 61 b in FIG. 3C. Optionally, the sides 61c of a flattened cross-section are rounded or otherwise shaped (e.g.,thickened) to prevent damage to the surrounding urethral and prostatetissue during delivery and/or implantation. Optionally, the shape of thewire has a non-constant cross-section, for example, thereby definingjoints at which the wire tends to bend. Optionally or alternatively, thecross-section is more complex than shown, for example, being undulatingin a trans-axial direction, optionally with a constant thickness.

Optionally, the distal tip of the wire (not shown) may be enlargedand/or rounded for the same purpose. However, in some embodiments, suchtip should be sufficiently sharp to pierce the tissue surrounded theurethra during implantation. In other embodiments, a separate sharp tipis provided by a delivery system, for example, as a holding tube.

The length of spiral wire 60 is determined by the longitudinal extent towhich the urethra is to be dilated in a particular area. Suchlongitudinal extent may be, for example, less than 1 cm long, between 1and 2 cm long, between 2 and 3 cm long or more, as required. Optionally,more than one spiral may be implanted along the urethra.

In an exemplary embodiment of the invention, the wire has a surfacecoverage (compared to a solid cylinder of same dimensions) of less than10%, between 10% and 40%, between 40% and 80%, or smaller orintermediate or larger coverages. Optionally, the coverage is selected,for example, according to prostate tissue being able to squeeze betweenadjacent helix turns and cause stenosis and/or according to maintaininga desired blood flow and/or reducing foreign material in the body. In anexemplary embodiment of the invention, the helix has a pitch of, forexample, 2, 4, 6, 10 or smaller, intermediate or large numbers of turnsper cm length. In some cases, helixes with as few as 1, 2 or 3 turns maybe used.

In an exemplary embodiment of the invention, the diameter of such acylinder is, for example, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm or smaller,intermediate or larger diameters (e.g., inner diameters or outerdiameters). The diameter is optionally selected to account for expectedfurther growth of the prostate.

In an exemplary embodiment of the invention, after implantation, flow inthe prostate is substantially unobstructed, for example, having a lumenof at least 1 mm, 2 mm or 3 mm in diameter over at least 60%, 70%, 80%or 90% of the prostate when urine is ejected form the bladder.Optionally, such implantation allows normal emptying of the bladder, orat least emptying of at least 60%, 70%, 80% or other percentages of thebladder.

The diameter 61 a (FIG. 3B) is optionally in the range of 0.2-3 mm. Theflattened width 61 b (FIG. 3C) is optionally in the range of 0.1-4 mm.The thickness 61 d (FIG. 3C) is optionally in the range of 0.01-2 mm

In an exemplary embodiment of the invention, the implant is selected ofmaterials and has material properties and dimensions suitable to resistdeformation by the prostate of more than 30%, 20% or 10%.

In an exemplary embodiment of the invention, when implanted, the wire isimplanted (e.g., selection wire helix diameter vs. urethra diameter) sothat there is a clearance of, on the average, 0.5 mm, 1 mm, 2 mm, 3 mm,or smaller, intermediate or larger amounts between the wire and theurethra. Optionally, the minima and/or maxima clearance are less than afactor of 4, 2, or 1.5 of such clearance.

In an exemplary embodiment of the invention, the surface of the wire issmooth. Optionally, the surface is made of a material or coated withmaterials that prevent tissue adhesion. In other embodiments, at leastpart of the wire is selected to have a surface that encourages surfaceadhesion, optionally, by being roughened. Optionally, the wire includesone or more outer barbs. Optionally, during implantation, such barbs orroughening are coated with a bio-dissolving material, such as a sugar,to prevent interference with implantation. Optionally or alternatively,the wire is delivered using a delivery tube which is pulled back afterthe wire is in place. Optionally, the tip and/or other parts of the wireinclude anchoring elements, optionally, as long as 1 mm or longer, whichextend away form the wire. Optionally or alternatively, such anchoringelements are soft filaments, rather than rigid barbs.

While the wire has been generally described as being uniform, it mayvary in shape, cross-section and/or material properties along itslength. Optionally, the delivered wire has a uniform diameter.Alternatively, the diameter is non-uniform, for example, being designedto flare towards a bladder neck or being designed to be smaller wherethe prostate is less compressive. Optionally or alternatively, thediameter is greater in the middle of the prostate.

Wire 60 is made of a biocompatible material, for example, nitinol,stainless steel, or chromium-cobalt. Optionally, the surface of the wiremay be coated or impregnated with a drug (e.g. sirolimus or paclitaxel)which is eluted over time, for example for between 1-7 days, 1-5 weeksor 1-4 months. Optionally, the drug is selected to prevent prostategrowth and/or otherwise treat the prostate. Optionally or alternatively,the drug is selected to enhance or prevent fibrosis. Optionally oralternatively, the drug is selected to prevent inflammation and/orinfection.. Optionally, wire 60 can also be made of a biodegradablematerial, for example, suitable plastics, such as a polylactate. In somecases, the implantation will cause fibrosis which will support theprostate without the need for foreign device. In some embodiments, thewire is inserted for treatment of the prostate and may be inserted in amanner which does not encircle the prostate.

Optionally, wire 60 is formed of or coated with a radioactive material(e.g., beta, alpha or gamma emitting material). Optionally, suchmaterial can serve to treat the prostate and/or prevent restenosis.Optionally, it may be formed of a material or have a structure (e.g.,coils) which can be heated by RF energy, for example, microwaves. Suchheating may be used, for example, for prostate shrinking and/or toassist in removal of the wire.

Optionally, wire 60 can have elastic, super elastic or shape-memoryproperties that enable it to expand during and after implantation toprovide further dilatation of the urethra. Optionally or alternatively,the wire is plastically deformable and is deformed by expanding aballoon in the urethra. Optionally, if restenosis occurs, furtherinflation is provided.

In some embodiments of the invention, the wire is a simple deviceoptionally formed of a single material and which is passive ormechanically reactive to pressures applied thereto.

FIGS. 3D-3F show a delivery device 48 according to some embodiments ofthe invention. Delivery device 48 includes a mounting tube 50 and aholder 52. Spiral wire 60 is positioned at the proximal end of mountingtube 50 (i.e., toward the physician) for delivery, and attached at itsproximal end to the distal end of holder 52. A slot 62 or other openingin holder 52 releasably receives the spiral wire. Holder 52 and mountingtube 50 with wire installed is optionally dimensioned to be slidable androtatable in working channel 14 to facilitate delivery and implantation.

FIG. 3D shows wire 60 and delivery device 48 still within workingchannel 14. FIG. 3E shows some features of the method of installation.In FIG. 3E, holder 52 has been pushed through working channel 14 usinghandle 54 to the point where it is outside the working channel at adesired location for implantation. Here, handle 54 is rotated andadvanced so the distal end 63 of wire 60 passes though the layer oftissue surrounding the urethra and is screwed into the prostate outsidethe urethra. Wire 60 is released from slot 62 once it has been screwedinto the prostate, and holder 52 is unscrewed (or pulled back) andwithdrawn into the working channel using handle 54. Delivery device 48may then be withdrawn from the working channel and the working channelwithdrawn from the urethra. Optionally, delivery device 48 may remain inthe working channel while the latter is withdrawn.

While not shown, the delivery tube may be expandable, e.g., with thewire mounted on the outside of a balloon or the outside of a tubemounted on a balloon, or a self expanding tube.

FIG. 3F shows spiral wire 60 after implantation, according to someembodiments of the invention. Optionally, by providing a clearancearound the urethra at 65, the urethra is allowed to decompress toprovide the desired dilation. Optionally, by effectively providing ashield around the urethra, the wire prevents further enlargement of theprostate from causing recompression of the urethra.

FIGS. 5A-5E, in conjunction with FIG. 4 illustrate a delivery deviceaccording to some embodiments, and a method of implantation. As shown inFIG. 5A, wire 60, which may be the same as that previously described, iscontained in a closely fitting delivery tube or sheath 64. This mayallow, for example, for the wire to be too soft for screwing into thetissue and/or having a surface not suitable for sliding past tissue asit is advanced. Optionally or alternatively, this allows for the wire tochange its configuration after insertion, for example, to expandradially. For delivery, it is placed on a mounting tube 50. A pusherwire 66 extends through a passage 67 in mounting tube 50. In someembodiments of the invention, use of sheath 64 facilitates using a wirewith a known configuration and enables insertion of a wire withshape-memory to further expand post delivery once sheath 64 is removed.The construction may otherwise be as previously described. Optionally,sheath 64 is formed of any biocompatible metal. and may be provided witha low friction coating, for example, as explained below.

Referring to FIG. 4 , a method of implantation of the embodiment of FIG.5A is shown which is also generally similar to that previously describedin connection with FIG. 1 , with one or more of the followingvariations. At 70, the wire 60 inserted in delivery tube 64, and at 72,the wire (inside the delivery tube), is installed on mounting tube 50,and pusher wire 66 is inserted. At 74 and 76, the working channel 14 isinserted, and the wire 60, delivery tube 64, and wire 66 are pushedthrough the working channel until the distal part of the delivery tubereaches the end of the working channel. Then, at 78, the delivery tubeand the mounting tube are rotated and advanced to screw the deliverytube with the wire still inside to the prostate around the urethra (seeFIG. 5B).

At 80, wire 60 is pushed out of the delivery tube 64 by pusher wire 66until the wire itself is implanted around the urethra FIG. 5C). Then, at84, delivery tube 64 is screwed back (or, for example, if soft, pulledback) into the working channel while the pusher wire 66 holds wire 60 inplace (FIG. 5D). A suitable handle or lock (not shown) may be providedon mounting tube 50 for this purpose. Optionally or alternatively, thetip of the wire anchors (e.g., by including a barb) and then deliverytube 64 can be pulled back without retracting the wire. At 86, theworking channel is removed.

FIG. 5E shows spiral wire 60 implanted around the urethra and providinga clearance at 69 to prevent recompression of the urethra.

FIG. 6 is a flow chart illustrating another delivery method suited forexample, for implanting a wire formed of one or more discrete elementssuch as arcs (e.g., c-shaped wires) as illustrated in FIGS. 7C-7E, and adelivery device for the method of FIG. 6 as shown in FIG. 8A. As contextfor the method of FIG. 6 , FIG. 7A shows in cross-section, prostate 200and a urethral passage 202 the generally triangular shape of which hasbeen compressed to the point of virtual blockage by enlargement of theprostate.

Referring to FIG. 8 , delivery device 204 includes a balloon 206optionally having a guide pocket 208 on its outer surface. A wire 210 inthe form of a generally C-shaped arc is attached to a delivery wire 212.An inflation tube 214 is provided to inflate balloon 206. All of theseare sized to pass through working channel 14 to a desired implantationsite.

Separate curved sections can be useful, for example, due to thevariation of the structure in different patients, thereby enablingflexibility in the installation of support for the urethra. As in thecase of the spiral wire, the curved sections may have round or flattenedcross-sections optionally, with rounded sides.

Referring to FIG. 6 , at 220, working channel 14 is installed. At 222,balloon 206 is inserted into the urethra through working channel 14 andthe balloon is inflated through inflation tube 214. This is shown inFIG. 7B, with all but corners 207 expanded to the contour of theexpanded balloon. Corners 207 are not fully expanded to illustrate asituation where inflation is insufficient. In this condition there issome danger of restenosis and/or danger of the wire transfixing theurethra.

At 224, a curved dilation segment of wire 210 (FIG. 7C) is attached todelivery wire 212 and pushed through working channel into guide pocket208 on balloon 206 (FIG. 8A). Other wire segment shapes can be used aswell, for example, substantially straight segments and segments with acurvature both for the circumference of the urethra and to support anaxial orientation. Thus, for example, a wire segment may be selected tobe a section of a circle or a section of a helix. Optionally, thesegment is curved, but is not part of a circle. For example, the sectionmay have a greater radius of curvature at one or both ends, than at acenter thereof. In another embodiment, the curvature of the element is amonotonic (increasing or decreasing) function along its length.

At 226, dilation wire 210 is pushed into and through guide pocket 208and the tissue around the urethra to desired position outside of theurethra (see FIG. 7C). Movement of delivery wire 212 may be controlledmanually or in any other suitable way, for example, with a foot pedal.The process is controlled visually or by ultrasound, for example.

In an exemplary embodiment of the invention, the insertion (e.g., and/ordirecting of guide) is circumferential. Optionally or alternatively, thedirection is at least in part axial. Optionally, the angle to the axisof the urethra is, for example, 90 (no axial component), 80, 70, 50, 30,or 10 degrees, or intermediate or smaller angles.

At 228, if more than one arc is to be implanted as shown in FIG. 7D,balloon 206 is rotated and/or translated to a next desired location forimplantation, and at 230, implantation through guide pocket 208 isrepeated the necessary number of times.

Optionally, the segments are inserted to have some overlap, for example,10%, 20%, 30%, 50%, 70% or smaller or intermediate amounts of overlap ina circumferential direction between two adjacent segments. Optionally oralternatively, such overlap is provided in an axial extent. In anexemplary embodiment of the invention, a surrounding of the urethra isprovided by, for example, 1, 2, 3, 4 or 5 segments. Optionally, at leastsome of the urethra is not enclosed, for example, 20% or 30% by angle,for example, a bottom section. Optionally, a density of segments isdifferent in different angular positions relative to urethra, forexample, being different by a factor of, for example, 1.3, 2, 3 orintermediate factors.

Optionally, a complete dilation device comprises 3, 5, 6, 8, 10, 15 orsmaller or intermediate or larger number of arc sections.

After insertion, diameter of the structural support and/or urethraldiameters can be, for example as for a single helical wire. Optionally,the shape of the support can deviate form that of a cylinder, forexample, as shown in FIG. 7E, the shape of a polygon with 3, 4, 5 orother numbers of sides.

At 232, delivery wire 212 is withdrawn through working channel 14. At234, balloon 206 is deflated and withdrawn into working channel 14. At236 working channel 14 is withdrawn. Optionally delivery wire 212 andballoon 206 are retained in the working channel while it is withdrawn.

FIG. 7E shows multiple arcs in place providing clearance to restoreurethral passage 238 to a dilated or semi-dilated condition. Aspreviously described, arcs 240 can prevent recompression of the urethradue to continued expansion of the prostate.

An alternative delivery device 204 a for a C-shaped wire is shown inFIG. 8B. This differs from the embodiment of FIG. 8A in that multiple(e.g., 2, 3, 4, 5 or more) guide pockets 208 a-208 c are provided onballoon 206, e.g., at multiple circumferential and/or axial positions.Each guide pocket is preloaded with each arc segment, optionallyattached to its own delivery wire 212 before insertion through workingchannel 14. Alternatively, a single pusher is used for all wires.Movement of delivery wires 212 may be controlled manually or in anyother suitable way, for example, with a foot pedal. The process isoptionally controlled visually or by ultrasound, for example.

Implantation device 204 a can avoid the need to rotate balloon 206 forcircumferential implantation of multiple arcs.

FIG. 10 shows a delivery method according to some embodiments using adelivery device 108 illustrated in FIG. 9 . The method of FIG. 10 anddelivery device 108 can be used for implantation of dilation devices inthe form of a spiral or of multiple C-shaped sections. This installationmethod employs an inflatable balloon, but instead of being locatedradially, it is positioned at one side of the urethra and expandsdiametrically. This has the potential benefit of having the mountingtube at the urethra wall, therefore enabling screwing the device in arotational movement, almost perpendicular to the insertion direction.Optionally or alternatively, a benefit of using a plain balloon isprovided, as the guiding mechanism may be provided on a separateelement.

Referring to FIG. 9 , delivery device 108 is comprised of a mountingtube 112, an attached handle 116 and a cage 114. Tube 112, carrying awire (e.g., segments or a complete helix) 110, shown, for example, as aspiral (noting that even a segment may be delivered as a spiral), ispositioned in cage 114 and delivered to an implantation site through aworking channel 109. Cage 114 prevents wire 110 from opening inside theworking channel. An opening 122 at the distal end of cage 114 isprovided to allow wire 110 to exit for implantation.

A balloon 120, for example, carried by a hollow expansion tube 118passing through handle 116 is positioned at the distal end of mountingtube 112. Optionally balloon 120 may be attached to mounting tube 112,for the purpose of fixed location of the balloon relatively to theopening 122 at the distal end of cage 114. Alternatively, the balloon isprovided on a separate element, optionally allowing relative movementand/or rotation.

As shown, balloon 120 has a relatively short axial extension.Alternatively, a greater axial extension, for example, of 5 mm, 10 mm,20 mm or other amount, is provided.

Referring now to FIG. 10 , at 90, working channel 109 is inserted in aurethra to be treated. At 92, dilation wire 110 is installed on mountingtube 112, and inserted into cage 114. At 96, cage 114 is insertedthrough working channel 109.

At 98, balloon 120 is expanded. As shown, cage 114 is positioned at oneside of the urethra, and balloon 120 is configured to expanddiametrically. This can be advantageous to allow direct insertion of thewire by a rotational movement at the desired direction. At 100, handle116 is rotated and advanced out of working channel 109 allowing wire 110to exit though opening 122 as mounting tube 112 is rotated. Optionally,rotation of mounting tube 112 allows wire 110 to pass through theurethra wall, and become implanted in the surrounding area of theprostate. Optionally or alternatively, a pusher wire (not shown) is usedto push wire 110. In an alternative embodiment, tube 112 is rotated,rotating wire 110 with it, while cage 114 is not rotated. Balloon 120 isoptionally fixed in position relative to mounting tube 112.

At 102, the implantation device 108 is withdrawn back into workingchannel 109. At 104, balloon 120 is deflated, and delivery device iswithdrawn through working channel 109 At 106, the working channel iswithdrawn. Delivery device 108 may optionally be retained in workingchannel 109 while it is being withdrawn.

In an exemplary embodiment of the invention, balloon 120 is expanded ata location with a known and/or fixed location relative to opening 122.Optionally, balloon 120 does not rotate, however, this may be allowed insome embodiments of the invention.

In an exemplary embodiment of the invention, a delivery system and/orone or more wires and/or wire sections are provided as a kit, optionallywith an indication for use (e.g., and/or printed instructions) insupporting a urethra and/or other particular organs. Optionally, such akit includes a balloon. Optionally or alternatively, such a kit includesa cystoscope. Optionally or alternatively, such a kit includes the wireor sections mounted on the delivery system.

As used herein the term “about” refers to ± 10 %.

The terms “comprises”, “comprising”, “includes”, “including”, “having”and their conjugates mean “including but not limited to”. This termencompasses the terms “consisting of” and “consisting essentially of”.

The phrase “consisting essentially of” means that the composition ormethod may include additional ingredients and/or steps, but only if theadditional ingredients and/or steps do not materially alter the basicand novel characteristics of the claimed composition or method.

As used herein, the singular form “a”, “an” and “the” include pluralreferences unless the context clearly dictates otherwise. For example,the term “a compound” or “at least one compound” may include a pluralityof compounds, including mixtures thereof.

The word “exemplary” is used herein to mean “serving as an example,instance or illustration”. Any embodiment described as “exemplary” isnot necessarily to be construed as preferred or advantageous over otherembodiments and/or to exclude the incorporation of features from otherembodiments.

The word “optionally” is used herein to mean “is provided in someembodiments and not provided in other embodiments”. Any particularembodiment of the invention may include a plurality of “optional”features unless such features conflict.

Throughout this application, various embodiments of this invention maybe presented in a range format. It should be understood that thedescription in range format is merely for convenience and brevity andshould not be construed as an inflexible limitation on the scope of theinvention. Accordingly, the description of a range should be consideredto have specifically disclosed all the possible subranges as well asindividual numerical values within that range. For example, descriptionof a range such as from 1 to 6 should be considered to have specificallydisclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numberswithin that range, for example, 1, 2, 3, 4, 5, and 6. This appliesregardless of the breadth of the range.

Whenever a numerical range is indicated herein, it is meant to includeany cited numeral (fractional or integral) within the indicated range.The phrases “ranging/ranges between” a first indicate number and asecond indicate number and “ranging/ranges from” a first indicate number“to” a second indicate number are used herein interchangeably and aremeant to include the first and second indicated numbers and all thefractional and integral numerals therebetween.

As used herein the term “method” refers to manners, means, techniquesand procedures for accomplishing a given task including, but not limitedto, those manners, means, techniques and procedures either known to, orreadily developed from known manners, means, techniques and proceduresby practitioners of the chemical, pharmacological, biological,biochemical and medical arts.

As used herein, the term “treating” includes abrogating, substantiallyinhibiting, slowing or reversing the progression of a condition,substantially ameliorating clinical or aesthetical symptoms of acondition or substantially preventing the appearance of clinical oraesthetical symptoms of a condition.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention, which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable subcombination or as suitable in any other describedembodiment of the invention. Certain features described in the contextof various embodiments are not to be considered essential features ofthose embodiments, unless the embodiment is inoperative without thoseelements.

Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and broad scopeof the appended claims.

All publications, patents and patent applications mentioned in thisspecification are herein incorporated in their entirety by referenceinto the specification, to the same extent as if each individualpublication, patent or patent application was specifically andindividually indicated to be incorporated herein by reference. Inaddition, citation or identification of any reference in thisapplication shall not be construed as an admission that such referenceis available as prior art to the present invention. To the extent thatsection headings are used, they should not be construed as limiting. Inaddition, any priority document(s) of this application is/are herebyincorporated herein by reference in its/their entirety

1. An apparatus for dilating a portion of a urethra surrounded by anenlarged prostate, the apparatus comprising: a dilation device; and adelivery device comprising a balloon, the delivery device beingconfigured: to deliver the dilation device and the balloon to theportion of the urethra, while the dilation device is disposed in ahelical configuration on the delivery device, and upon the balloon andthe dilation device being disposed at the portion of the urethra: toexpand the balloon, thereby expanding the portion of the urethra, tocause the dilation device to radially expand from the helicalconfiguration to an arc configuration, and subsequently, to implant thedilation device, from outside the balloon, into tissue of the prostatesurrounding the portion of the urethra, while the portion of the urethrais expanded by the balloon.
 2. The apparatus according to claim 1,wherein the delivery device is configured to implant the dilation deviceinto the tissue of the prostate surrounding the portion of the urethraby screwing the dilation device into the tissue of the prostatesurrounding the portion of the urethra.
 3. The apparatus according toclaim 1, wherein the delivery device is configured to implant thedilation device into the tissue of the prostate surrounding the portionof the urethra by pushing the dilation device into the tissue of theprostate surrounding the portion of the urethra.
 4. The apparatusaccording to claim 1, wherein the delivery device comprises an overtube,and wherein the delivery device is configured to implant the dilationdevice into the tissue of the prostate surrounding the portion of theurethra by advancing the dilation device into the tissue of the prostatesurrounding the portion of the urethra using the overtube.
 5. Theapparatus according to claim 1, wherein the dilation device isconfigured to expand post-implantation.
 6. The apparatus according toclaim 1, wherein the dilation device comprises one or more separatearcuate-shaped sections.
 7. The apparatus according to claim 1, whereinthe dilation device comprises a material configured to expand outwardlyaround the urethra during and/or after implantation.
 8. The apparatusaccording to claim 1, wherein the balloon is configured to shape theurethra prior to or during the implanting of the dilation device.
 9. Theapparatus according to claim 1, wherein the delivery device isconfigured not to rotate the balloon during the implanting of thedilation device.
 10. The apparatus according to claim 1, wherein thedilation device is sized such that, upon being implanted into the tissueof the prostate surrounding the portion of the urethra, the dilationdevice does not interfere with an inner bladder valve.
 11. The apparatusaccording to claim 1, wherein the dilation device is sized such that,upon being implanted into the tissue of the prostate surrounding theportion of the urethra, the dilation device provides clearance betweenthe enlarged prostate and a lumen of the urethra and preventsrecompression of the urethra due to further enlargement of the prostate.12. The apparatus according to claim 1, wherein the dilation device hasa substantially flat cross-section.
 13. The apparatus according to claim1, wherein the dilation device comprises a plastically-deformablematerial and the delivery device is configured to cause the dilationdevice to radially expand from the helical configuration to the arcconfiguration by inflating the balloon.
 14. The apparatus according toclaim 1, wherein the dilation device comprises an elastically-deformablematerial, wherein the delivery device comprises a mounting deviceconfigured to hold the dilation device within the delivery device, andwherein the delivery device is configured to cause the dilation deviceto radially expand from the helical configuration to the arcconfiguration by releasing the dilation device from the mounting device.15. The apparatus according to claim 11, wherein the dilation device issized such that, upon being implanted into the tissue of the prostatesurrounding the portion of the urethra, there is a portion of theurethra that is not surrounded by the dilation device at the bottom ofthe urethra.
 16. The apparatus according to claim 1, wherein thedilation device is sized such that, upon being implanted into the tissueof the prostate surrounding the portion of the urethra, no more than 30%by angle of the portion of the urethra is not surrounded by the dilationdevice.
 17. The apparatus according to claim 16, wherein the dilationdevice is sized such that, upon being implanted into the tissue of theprostate surrounding the portion of the urethra, there is a portion ofthe urethra that is not surrounded by the dilation device at the bottomof the urethra.